Pre-draw crimping method and article



1970 A. A. TENNISON, SR

FEE-DRAW CRIMPING METHOD AND ARTICLE 2 Sheets-Sheet 1 Filed Sept. 18, 1967 INVENTOR ALF/$360,! 7fAlN/J'0/V, M.

J 27, 1970 A. A. TENmsoN. SR

PRE'DRAW CRIMPING METHOD AND ARTICLE 2 Sheets-$heet 2,

Filed Sept. 1 19s? United States Patent O 3 491,573 PRE-DRAW CRIMPIN G METHOD AND ARTICLE Alfred A. Tennison, Sr., Texarkana, Ark., assignor to Alfred A. Tennison, Jr., Texarkana, Ark. Filed Sept. 18, 1967, Ser. No. 668,562 Int. Cl. B21c 37/02 US. Cl. 72-348 2 Claims ABSTRACT OF THE DISCLOSURE A pre-draw crimping method and article in which the method includes the pre-crimping of a plain sheet of metal to provide hills and valleys or corrugations for additional fullness in the metal sheet before it is drawn and shaped to its final configuration.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to metal working and particularly to the stamping and shaping of metal in the manufacture of miscellaneous patterns in roofing including ridge rolls, edgings, corners, sidings, gambrel fiashings, valleys, gutters and related accessories.

Description of the prior art Prior art methods and articles have not been satisfactory due to fatigue and rupturing of the metal when stretched and also because of the fact that the prior art has failed to provide needed complex patterns having pronounced hills and valleys and it has been customary either to use plastic or rubber fillers between portions of roofing, siding, ridge rolls and accessories or else to cut notches in the ridge rolls or other accessories so that the edges would at least loosely fit the design or siding with which it is to be used.

SUMMARY OF THE INVENTION The invention is a method and an article which includes crimping of a plain sheet of metal or blank prior to the drawing and shaping of the same, whether deep drawn or not, so that the metal when drawn will retain the desired configuration and not spring back after being struck by a forming die, as is frequently the case if the blank is not pre-crimped or provided with alternate hills and valleys or raised and depressed portions prior to its being drawn. The pre-draw crimping includes the use of either simple conventional crimping with crimps or corrugations extending in the same direction and unconventional crimping in which the crimps or corrugations extend in various directions. In other words, one or more sets of crimps is applied, including after and on top of the other but at varying angle or angles. This results in an embossed appearance upon the face of the sheet metal and also includes another form of non-conventional crimping in which portions of a sheet of metal are crimped with one or more patterns of indentations and in which the various portions of the sheet may have different designs and depths as well as different angles of application.

It is an object of the invention to provide a method of drawing and shaping metal for specific purposes and to provide a resulting article, which method will insure that the metal can readily be conformed to the desired configuration without tearing or rupturing by providing an additional fullness in the metal by forming hills and valleys or corrugations so that when the metal is finally drawn and shaped there will be sufficient fullness to allow for the necessary drawing and shaping operations, thus permitting the use of metals of lighter gauge which ice otherwise would not be usable due to the lack of necessary strength with favorable influence both on the cost and quality of the product.

A further object of the invention is to provide a plain smooth surfaced sheet of metal with hills and valleys having additional fullness to enable it to withstand the stress of a press-brake, or roll former, unlike the plain sheet, and which prepared sheet can be extended or reduced in size and can be given the depth and design according to the shape of the end product and'without excessive bulging and warping.

A further object of the invention is to simplify the deep drawing of the metal and to provide a simple readily available prepared sheet or blank having hills and valleys and the necessary fullness to enable it to be readily subjected to drawing and shaping operations in completing the finished article, thus reducing costs, enabling use of lower grade metal which could not otherwise be used and eliminating the necessity for higher cost and quality metal, as well as simplifying the operation so that a less degree of skill and reduced amount of labor is required in its production and with any need for fillers or notches in the edge of the metal eliminated.

A still further object of the invention is to provide an end product of uniform consistency and improved quality with the necessary formations or configuration and allowing the use of the same dies and sets employed in the drawing and forming process which ordinarily would result in the splitting or bulging of the metal if the precrimping were not employed.

Other objects and advantages of the invention will be apparent from the following description considered in conjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of a conventional sheet of metal;

FIG. 2, a similar View after having been pressed or stamped to give it corrugations;

FIG. 3, a detailed section on the line 33 of FIG. 2;

FIG. 4, a detailed perspective of the sheet of FIG. 2 after it has been subjected to a stamping and forming die to give it its desired configuration;

FIG. 5, an end view of the sheet of FIG. 4;

FIG. 6, a perspective of a sheet after it has been subjected to a stamping die to provide corrugations in two directions;

FIG. 7, the sheet of FIG. 6 after it has been subjected to a die for getting its final configuration;

FIG. 8, a perspective of a sheet when subjected to a die to provide the necessary corrugations to give it fullness prior to its final shaping;

FIG. 9, the sheet of FIG. 8 after it has been subjected to a die to give it its final configuration;

FIG. 10, a perspective of a four-way corrugated sheet with the necessary fullness to enable it to be finally shaped; and

FIG. 11, the sheet of FIG. 10 after it has been subjected to a die to give it its final configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With continued reference to the drawings, a plain smooth-surfaced sheet of metal 10 is provided in which are formed corrugations or hills and valleys 11 and 12 to provide the metal with additional fullness so that when subjected to deep drawing there will be adequate metal present and thus the likelihood of tearing or rupturing will be avoided.

In FIGS. 4 and 5 the metal sheet 10 is illustrated after it has been deep drawn to provide a ridge roll portion 13 and right angular reinforcing ribs 14. The roll por- 3 tions 13 and ribs 14 provide sufficient stiffness to the product to prevent its readily buckling, twisting and warping. In this embodiment the product is adapted to be disposed at the top or over the apex of the roof with the roll portions overlapping and nesting together in a manner to exclude the weather.

Instead of the product illustrated in FIGS. 4 and 5 with a single side portion and a fragmentary ridge roll portion, a product such as illustrated in FIGS. 6 and 7 may be provided. In this the sheet 10 may have hills and valleys or corrugations across the sheet, and lengthwise of the sheet may be hills and valleys 16 located centrally of the sheet. The sheet thus formed may be readily deep drawn and shaped to give it the ridge roll portion 17 and the reinforcing ribs 18 and angular depending side portions. Thus a relatively stiff end prodnet is produced from the flat sheet with the angular crimping therein.

In FIG. 8 is disclosed a pre-crimpting sheet having portions 20 and 21 at right angles to each other and forming a T. Each of the portions 20 and 21 is provided with longitudinal hills and valleys or corrugations 22 and 23 to provide the desired fullness when the precrimped sheet is given its final drawing to provide roof portions with angular sides 24 and 25. The sides 24 and 25 are at right angles to each other and the finished product is relatively stiff, although due to the hills and valleys or corrugations lighter weight lower grade metal sheet can be used, and due to the fullness there will be no undue stretching or rupturing of the metal along such sharply bent portions 26.

In FIG. 10 is illustrated a four-way roof structure instead of a three-Way as illustrated in FIGS. 8 and 9. In this four-way roof structure the four right-angular portions 27, 28, 29 and 30 are provided with right-angular fold lines 31 and 32 which form the valleys 33 in the end product of FIG. 11. Each of portions 27, 28, 29 and 30 is provided with longitudinal hills and valleys or corrugations 34 to give it the necessary fullness so that when it is deep drawn or shaped to give it the configuration illustrated in FIG. 11 the metal may readily be given its final shape with a minimum of stretching, with uniform quality, and with depending inclined side portions 34 which conform to the configuration of the roof to which the end product is applied.

Normally, when a sheet of relatively stiff metal is deformed in accordance with prior art practice, the metal is stretched to the shape of the die. Obviously the stretching of the metal reduces the thickness of the deformed portion. In certain operations, particularly deep drawing operations, a single draw would stretch the metal beyond its elastic limits and a tear or rupture would result. Accordingly, it has been necessary to provide a plurality of sequential draws or separate drawing operations with each draw being deeper than the previous draw until the desired configuration is obtained.

By practicing the method of the present invention, the pre-crimping operation will provide additional metal in the area of the draw, so that when the sheet is placed within a die and the die is closed under pressure, the excess metal created by the crimps will flow into the die and permit the draw to be formed in a single operation. Obviously, the excess metal will increase the wall thickness of the deformed portion and will result in a stronger structure.

It will be understood from the foregoing that various shapes and configurations may be employed and that the hills and valleys may be disposed angularly relative to each other or may overlie each other. Also, it will be apparent that the hills and valleys may be of a predetermined height and depth in accordance with the depth of the draw and that the number of hills and valleys may be varied to provide varying quantities of material. In other words, a few shallow hills and valleys may be provided for a shallow draw, and many relatively deep hills and valleys may be provdied for a deep draw.

It will be obvious to one skilled in the art that various changes may be made in the described embodiments of the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated in the drawings and described in the specification, but only as indicated in the accompanying claims.

What is claimed is:

1. A method of drawing and shaping sheet metal structures comprising the-steps of providing a sheet of metal, applying a first set of crimps in one direction along at least a portion of said sheet of metal, said first set of crimps being generally parallel with each other to provide materiai for a deep draw along said one direction, applying a second set of crimps to said sheet of metal at an angle to said first set of crimps, the crimps on said second set being generally parallel with each other, and shaping said sheet by a drawing operation so that portions of said sheet are out of the plane of other portions, whereby said sheet of material can be formed in a single shaping operation without rupture of the metal and the portion of said sheet defined by said second set of crimps will be disposed at an angie to the portion of said sheet defined by said first set of crimps.

2. The method of claim 1 in which said crimps are of predetermined size in accordance With the depth of the draw.

References Cited UNITED STATES PATENTS Re. 16,115 7/ 1925 Schlafly 72-379 511,392 12/1893 White 72-379 1,255,266 2/1918 Zawardzky 72-379 2,735,390 2/1956 Engel 72379 3,144,974 8/1964 Eichner et al 72379 CHARLES W. LANHAM, Primary Examiner L. A. LARSON, Assistant Examiner US. Cl. X.R. 72-379 

